Valve announces that Half-Life 2: Episode One is now available via
Steam:

Valve Launches First of an Episodic Trilogy

Bellevue, WA, June 1, 2006 - Valve®, developer of the blockbuster series
Half-Life® and Counter-Strike™, announced Half-Life® 2: Episode One is now
available via Steamgames.com for just $19.95 and at retail outlets around the
world.

The first in a trilogy of episodic games, Episode One reveals the aftermath of
Half-Life 2 and launches a journey beyond City 17. Episode One does not require
Half-Life 2 to play and also includes a first look at Episode Two, which will
ship by year's end.

In addition to the new single player experience, two multiplayer games are
included. And those who purchase Episode One will have free access via Steam (www.steamgames.com)
to Half-Life 2: Lost Coast, the interactive technology demo that introduces High
Dynamic Range lighting to the SourceTM Engine, Valve's award-winning game
technology.